Search Results (31)

The study investigates the potential of enhancing gypsum board properties through the integration of hemp hurds and glass fibers. The investigation focuses on evaluating the composite material’s density, water absorption, flexural strength, compressive strength, and thermal performance. Experimental results demonstrate a reduction in gypsum composite density and improved thermal insulating properties with the introduction of hemp hurds. Water absorption, a significant drawback of gypsum boards, is mitigated with hemp hurds, indicating potential benefits for insulation efficiency. For mechanical tests, the gypsum ceiling board at approximately 5% by weight exhibits a flexural strength value exceeding the minimum average threshold of 1 MPa and the highest average compressive strength at 2.94 MPa. Thermal testing reveals lower temperatures and longer time lags in gypsum boards with 5% hemp hurds, suggesting enhanced heat resistance and reduced energy consumption for cooling. The study contributes valuable insights into the potential use of hemp hurds in gypsum-based building materials, presenting a sustainable and energy-efficient alternative for the construction industry. Full article

Gypsum-based composites were prepared via a slurry casting process using construction gypsum as the binding material and poplar fibers as reinforcing material. The effects of different fiber content and curing time on the mechanical properties, water resistance, and flame retardancy of these composites were investigated, and the influence mechanism was characterized by infrared spectroscopy, scanning electron microscopy, and X-ray diffractometry. The results showed that the best composite mechanical strength was achieved with 10% poplar fiber- content, and the absolute dry flexural and compressive strengths reached 3.59 and 8.06 MPa, respectively. Compared with pure gypsum, the flexural strength and compressive strength increased by 10% and 19%, respectively. The inclusion of fibers somewhat prevented the migration of free water within the composites and enhanced their water resistance. At 10% fiber content, the composite’s 24 h water absorption rate was 34.3%, 8% lower than that of pure gypsum, with a softening coefficient of 0.55. However, fiber content increases the porosity of gypsum-based composites. When heated, this increased porosity accelerates’ heat conduction within the matrix, raising the peak and total exothermic rates, thereby weakening the composites’ inherently flame-retardant properties. Poplar-fiber-reinforced gypsum-based composites offered superior performance in commercial applications, compared to pure gypsum board, providing a sustainable and green alternative for ceilings, partitions, and other applications, while broadening the prospects for gypsum-based composites in the engineering field. Full article

In recent times, there has been a notable surge in the interest in promoting environmentally conscious products, particularly within the building industry where the focus has shifted towards sustainable materials. In this study, as a sustainable building material, ceiling tiles have been fabricated as a composite board containing waste materials, namely waste paper, sawdust, recycled polyethylene terephthalate (PET), and epoxy resin, and characterized comprehensively through physical and mechanical tests, density, thickness swelling (TS), modulus of elasticity (MOE), modulus of rupture (MOR), and flexural strength (FS) for product stability. A total of nine composites were fabricated with different ratios through molding techniques, and the characterization results were compared to determine the optimized stable ratio of composite composition. The composition of 25% waste paper, 15% sawdust, 10% recycled PET, and 50% epoxy resin presented the maximum FS compared to the other composite ratios. Water absorption (WA) and thickness swelling were evaluated after immersion durations of 1–24 h. The findings revealed that as the density increased, the sawdust content within the matrix decreased from 25–35%. Concurrently, an increase in recycled PET content resulted in decreased water absorption and thickness swelling. Significantly, the MOE, MOR, and FS demonstrated optimal values at 864.256 N/mm², 12.786 N/mm², and 4.64 MPa, respectively. These observations represent the excellent qualities of this hybrid composite board, particularly in terms of sustainability, stability, and water absorption capacity. Moreover, its lightweight nature and ability to support ceiling loads further enhance its appeal for construction applications. This study not only advances the discourse on sustainable construction materials but also fosters opportunities for broader acceptance and innovation within the industry. Full article

Measuring postural control in an upright standing position is the standard method. However, this diagnostic method has floor or ceiling effects and its implementation is only possible to a limited extent. Assessing postural control directly on the trunk in a sitting position and consideration of the results in the spectrum in conjunction with an AI-supported evaluation could represent an alternative diagnostic method quantifying neuromuscular control. In a prospective cross-sectional study, 188 subjects aged between 18 and 60 years were recruited and divided into two groups: “LowBackPain” vs. “Healthy”. Subsequently, measurements of postural control in a seated position were carried out for 60 s using a modified balance board. A spectrum per trail was calculated using the measured CoP tracks in the range from 0.01 to 10 Hz. Various algorithms for data classification and prediction of these classes were tested for the parameter combination with the highest proven static influence on the parameter pain. The best results were found in a frequency spectrum of 0.001 Hz and greater than 1 Hz. After transforming the track from the time domain to the image domain for representation as power density, the influence of pain was highly significant (effect size 0.9). The link between pain and gender (p = 0.015) and pain and height (p = 0.012) also demonstrated significant results. The assessment of postural control in a seated position allows differentiation between “LowBackPain” and “Healthy” subjects. Using the AI algorithm of neural networks, the data set can be correctly differentiated into “LowBackPain” and “Healthy” with a probability of 81%. Full article

Currently, the predominant thermal insulation materials in the construction industry are primarily derived from inorganic sources. While these materials demonstrate commendable thermal insulation capabilities, their widespread use raises significant environmental concerns. The utilization of wood fiber materials presents a promising solution to mitigate these drawbacks. This study focuses on the fabrication of biodegradable fiber insulation board (BFIB) using camphor branches. The manufacturing process avoids the use of chemical additives, employing a physical method that utilizes hot pressing and relies on the formation of intermolecular hydrogen and hydroxide bonds between the fibers. The study evaluates the influence of applied pressure on the properties of BFIB. SEM images reveal that, with an increase in applied pressure, the fibers exhibit a more regular pattern, subsequently enhancing the mechanical properties, hygric behavior, and fire resistance properties of BFIB. As an environmentally friendly and renewable material, BFIB holds the potential to substitute conventional insulation materials. It is particularly intriguing for energy-saving purposes when applied as building insulation for walls or ceilings. Full article

Smart vapour barriers enable building envelopes to dry toward the interior side. This property can be used in compact wooden roofs to create more slender structures by placing the wooden load-bearing elements inside the insulation layer. There is, however, some concern that the ceiling assembly on the interior side may inhibit inward drying by trapping moisture between the vapour barrier and the ceiling boards. This article examined the water vapour resistance of gypsum boards painted with two, four, and six layers of typical ceiling paints. WUFI^® 2D simulations were conducted to assess the risk of mould growth in compact wooden roofs with painted board ceilings. It was found that a painted ceiling board may exhibit an equivalent stagnant air layer thickness (s_d value) between 0.074 m for two layers of the most vapour-open paint and 0.53 m for six layers of the least vapour-open. For an unpainted board, the s_d value was measured to be 0.071 m. The difference was not found to make a substantial impact on the drying of a typical compact wooden roof. The application of paint may cause the assembly to dry at a slightly slower rate but was not found to present a notably higher risk of mould growth, even under unfavourable conditions. Full article

Plasterboard is an important building material in the construction industry because it allows for quick installation of walls, partitions, and ceilings. Although a common material, knowledge about its performance related to modern polymers and fabrication conditions is still lacking. The present work analyzes how some manufacturing factors applied during the plaster board fabrication impact on some plasterboard properties, including water absorption, flexural strength, and thermal conductivity. The manufacturing variables evaluated are the dose (D) of polymethylhydrosiloxane (PMHS), the agitation time of the mixture (H), and the drying temperature of the plaster boards after setting (T). The results suggest that factors D, H, and T induce changes in the porosity and the morphological structure of the calcium sulfate dihydrate crystals formed. Performance is evaluated at two levels of each factor following a statistical method of factorial experimental design centered on a cube. Morphological changes in the crystals of the resulting boards were evaluated with scanning electron microscopy (SEM) and the IMAGEJ image analysis program. Porosity changes were evaluated with X-ray microcomputed tomography (XMT) and 3D image analysis tools. The length-to-width ratio of the crystals decreases as it goes from low PMHS dosage to high dosage, favoring a better compaction of the plasterboard under the right stirring time and drying temperature. In contrast, the porosity generated by the incorporation of PMHS increases when going from low-level to high-level conditions and affects the maximum size of the pores being generated, with a maximum value achieved at 0.6% dosage, 40 s, and 140 °C conditions. The presence of an optimal PMHS dosage value that is approximately 0.6–1.0% is evidenced. In fact, when comparing trails without and with PMHS addition, a 10% decrease in thermal conductivity is achieved at high H (60 s) and high T (150 °C) level conditions. Water absorption decreases by more than 90% when PMHS is added, mainly due to the hydrophobic action of the PMHS. Minimum water absorption levels can be obtained at high drying temperatures. Finally, the resistance to flexion is not affected by the addition of PMHS because apparently there are two opposing forces acting: on one hand is the decrease in the length–width ratio giving more compactness, and on the other hand is the generation of pores. The maximum resistance to flexion was found around a dosage of 0.6% PMHS. In conclusion, the results suggest that the addition of PMHS, the correct agitation time of the mixture, and the drying temperature reduce the water absorption and the thermal conductivity of the gypsum boards, with no significant changes in the flexural resistance. Full article

When performing indoor tasks, miniature swarm robots are suffered from their small size, poor on-board computing power, and electromagnetic shielding of buildings, which means that some traditional localization methods, such as global positioning system (GPS), simultaneous localization and mapping (SLAM), and ultra-wideband (UWB), cannot be employed. In this paper, a minimalist indoor self-localization approach for swarm robots is proposed based on active optical beacons. A robotic navigator is introduced into a swarm of robots to provide locally localization services by actively projecting a customized optical beacon on the indoor ceiling, which contains the origin and the reference direction of localization coordinates. The swarm robots observe the optical beacon on the ceiling via a bottom-up-view monocular camera, and extract the beacon information on-board to localize their positions and headings. The uniqueness of this strategy is that it uses the flat, smooth, and well-reflective ceiling in the indoor environment as a ubiquitous plane for displaying the optical beacon; meanwhile, the bottom-up view of swarm robots is not easily blocked. Real robotic experiments are conducted to validate and analyze the localization performance of the proposed minimalist self-localization approach. The results show that our approach is feasible and effective, and can meet the needs of swarm robots to coordinate their motion. Specifically, for the stationary robots, the average position error and heading error are 2.41 cm and 1.44°; when the robots are moving, the average position error and heading error are less than 2.40 cm and 2.66°. Full article

In recent years, cases of the improper utilization of steel furnace slag have been widely reported, resulting in a crisis of nowhere for recycled resources such as inorganic slag. The misplacement of resource materials that originally had sustainable-use value not only has a great impact on society and the environment but also greatly reduces industrial competitiveness. To solve the dilemma of steel furnace-slag reuse, it is critical to find solutions to the stabilization of steelmaking slag under the innovative thinking of the circular economy. In addition to enhancing the reuse value of recycled resources, the balance between economic development and environmental impact is also crucial. The high-performance building material could provide a solution based on a high-value market. With the development of society and the increasing requirements for quality of life, the requirements for the soundproof and fireproof performance of lightweight decorative panels common in cities have gradually become popular. Therefore, the high performance of fire retardant and soundproofing could be the main development focus of high-value building materials to ensure circular economic feasibility. This study continues the research results of the application of inorganic re-cycled engineering materials in recent years, and the application of electric-arc furnace (EAF)-reducing slag to the development of base materials for reinforced cement boards, in order to complete the development of high-value panels with fireproof and sound-insulation properties in line with the engineering characteristics of the boards. The research results showed the optimization of the proportions of the cement boards with EAF-reducing slag as a raw material. The proportions of EAF-reducing slag to fly ash at ratios of 70:30 and 60:40 all met the requirements of ISO 5660-1 Class I flame resistance; the sound transmission loss in the overall frequency band can reach more than 30 dB, which is higher by 3–8 dB or more than the same board with similar specifications (such as 12 mm gypsum board) in the present building-materials market The products could be developed into building partitions and ceiling decoration boards with high performance in terms of fire retardant and soundproofing values, and also reduce the use of natural raw materials by more than 35%. The results of this study could meet environmental compatibility targets and contribute towards greener buildings. This model of circular economics would achieve energy reduction, emissions reductions, and be environmentally friendly. Full article

Recently, the issue of the gender gap in dentistry and in the leadership in the dental field has placed new challenges on dental profession representatives and politicians. Indeed, the inequity between genders in healthcare workforces represents a limit to the progression of those in the professions, inhibiting talented colleagues from accessing high positions in the academic world and not providing adequate role models to inspire future generations. The Italian population practicing dentistry in 2021 was composed of 74% males and 26% females. The aim of this study is to analyze the level of the gender gap in the dental field in Italy by focusing on the gender distribution of professional leaders in institutional category associations and invited speakers at dental conferences accredited for the Continue Education in Medicine program. The search strategy considered three different fields in the national dentistry scene: the dental committee boards, the union category associations, and the cultural field. The roles in the dental boards were retrieved from the website of the National Medical and Dental Committee from 2018 to 2022; the roles in the union category associations at the provincial, regional, and national levels were retrieved from the related web pages, considering the period from 2018 to 2021; and the information about the speakers at national conferences from 1 January 2019 to 31 December 2021 was retrieved from the National Agency for Regional Health Services (Agenzia nazionale per i servizi sanitari regionali (AGENAS)) websites. The extracted data were grouped and examined using descriptive statistics (frequency), and due to the categorical nature of the data, non-parametric tests (chi-square tests) were used to assess any differences between the two genders. The null hypothesis was that there were no statistical differences between the two genders’ distributions. A p-value was considered significant when <0.05. In addition, aiming to understand the representation of male and female dentists, a comparison of the distributions of males and females in the dental boards with the percentages of female and male dentists operating in Italy in 2021 was performed using a binomial test. The analysis of the data regarding the composition of the dental boards and of the union category association boards revealed a statistically significant difference in the distribution of the roles between the two genders at the regional and local levels, with a p-value of <0.05, and a significantly low representation of the women practicing dentistry (p < 0.05). In Italy, women practicing dentistry are underrepresented in dental organizations and in cultural events, given the low numbers of female dentists in leadership and/or speaker roles in the years 2018–2021. Even though the glass ceiling effect continues to affect Italian female dentists, initiatives and political measures have been taken to improve this condition and reach gender equity. Full article

Equality Gender balance between men and women is one of the most current controversial issues in recent years that provokes a number of debates, questioning whether it really exists or is instead a myth. This article examines how the issue is regulated by European Union (EU) law and to what extent the legal framework is implemented into the current composition and work of European institutions. The trend of women’s empowerment is examined on the example of some of the EU institutions, mainly the European Commission and the European Parliament. The authors point out that, at the moment, three of the institutions included in the single institutional framework of the EU are headed by women—Ursula von der Leyen, Roberta Metsola, and Christine Lagarde—and the European Ombudsman is a woman. This represents an undisputed achievement in the field of gender balance at a higher political level within the EU as well as the appointment of the first-ever commissioner for equality. The newest secondary legislation framework is observed: Directive 2019/1158/EU on work–life balance and the latest development with regard to the female representation on corporate boards (Women on Boards Directive). The article also concludes that while some of the institutions have managed to make steps towards a real gender balance during recent years, not all of the Member States have experienced such progress, and this is evident in the organization and work of the Council of the EU. Although the introduction of quotas for women on company boards has been assessed ambiguously, it represents a necessary action ‘to break the glass ceiling’ and would give a new impetus to women’s empowerment within the EU. Full article

Standard building practices commonly use gypsum-based drywall panels on the interior wall and ceiling applications as a partition to protect the components of a wall assembly from moisture and fire to uphold the building code and ensure safety standards. Unfortunately, gypsum-based drywall panels have poor resistance to water and are susceptible to mold growth in humid climates. Furthermore, the accumulation of drywall in landfills can result in toxic leachate impacting the surrounding environment. A proposed solution to the pitfalls of gypsum-based drywall arises in its substitution with a new lightweight composite honeycomb sandwich panel. This study aimed to develop sandwich panels with improvements in flexural strength and thermal insulating properties through the combined use of cementitious binder mix and kraft-paper honeycomb structures. The proposed alternative is created by following standard practices outlined in ASTM C305 to create cement panels and experimenting with admixtures to improve the material performance in order to cater to a drywall panel application. The kraft-paper honeycomb structure is bonded to cured cementitious panels to create a composite “sandwich panel” assembly. The results indicate that the sample flexural strength performed well after 7 days and exhibited superior flexural strength at 28 days, while providing a substantial increase in R-value of 5.84 m²K/W when compared to gypsum-based panels, with an R-value of 5.41 m²K/W. In addition, the reinforced kraft-paper honeycomb with a thick core and addition of flax fibres to the cementitious boards possesses better thermal conductivity, with a reduction of 42%, a lower density, and a lower water vapour transmission in comparison to the thin kraft-paper honeycomb sandwich panel. Full article

Multilayer objects with different interfaces are quite typical for architectural heritage, and from them may be inferred the age, production process, and deterioration mechanism through analyzing characteristic compositions with advanced analytical techniques. The Meiwu ceiling in the Hall of Mental Cultivation of the Palace Museum was found to contain many paper-based layers during conservation. Once several surface strata were detached, a colorful layer of printed fabric textile was discovered integrally. Through microscopic observation and micro-attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) imaging, the overall structure consisted of 11 layers, namely, bast paper, cotton wiring, xuan paper, cotton printed fabric, two yellow board papers, bamboo paper, three wood pulp paper and surface coatings, and starch was considered as an organic adhesive. For identification of the printed fabric’s color palette, ultra-performance liquid chromatography (UPLC) combined with high-resolution quadrupole time-of-flight (QTOF) technology, non-invasive macro X-ray fluorescence (MA-XRF) and desorption electrospray ionization mass spectrometry imaging (DESI-MSI) were applied in situ. Seven industrial synthetic dyes, including auramine O, malachite green, and eosin Y with corresponding by-products, as well as chromium-based pigments considered as dark draft line, were confirmed. By X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), and micro Fourier transform infrared spectroscopy (micro FTIR, other results showed chalk soil and talc for the outermost coating. According to the synthetic time of industrial dyes and degradation degree of paper, there were at least four occurrences and their specific time periods were speculated. Full article

In this study, the effects of multi-perforated gypsum boards on floor impact noises were investigated in a box-type test building and an actual apartment building. In a box-type test building with 150 mm thick slab, various design factors such as hole pattern, hole size, opening ratio, backing, or finishing materials were considered. Heavy-weight impact sources of bang machine and rubber ball were employed. The test procedure followed KS F 2810-2, and then, a single number rating was derived in accordance with KS F 2863-2. As a result, reduction of heavy-weight impact noise by applying multi-perforated gypsum boards as a ceiling material was expected maximumly up to 3 dB for bang machine and 5 dB for rubber ball. Regarding the reduction of floor impact sounds at frequencies above 125 Hz, the installed area of the employed multi-perforated gypsum board was shown as the most dominant factor. Then, an in situ investigation using standard impact sources and five children was carried out in an actual living space of an actual apartment dwelling unit. Comparing before and after installation of multi-perforated gypsum board, 1–2 dB of heavy-weight impact noises was reduced. In addition, subjective impressions of the reduced impact noise were discussed based on the field questionnaire survey using actual children’s running situations. Full article

In indoor localization there are applications in which the orientation of the agent to be located is as important as knowing the position. In this paper we present the results of the orientation estimation from a local positioning system based on position-sensitive device (PSD) sensors and the visible light emitted from the illumination of the room in which it is located. The orientation estimation will require that the PSD sensor receives signal from either 2 or 4 light sources simultaneously. As will be shown in the article, the error determining the rotation angle of the agent with the on-board sensor is less than 0.2 degrees for two emitters. On the other hand, by using 4 light sources the three Euler rotation angles are determined, with mean errors in the measurements smaller than 0.35° for the x- and y-axis and 0.16° for the z-axis. The accuracy of the measurement has been evaluated experimentally in a 2.5 m-high ceiling room over an area of 2.2 m${}^2$ using geodetic measurement tools to establish the reference ground truth values. Full article